1 //===-- LLVMContextImpl.cpp - Implement LLVMContextImpl -------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file implements the opaque LLVMContextImpl.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "LLVMContextImpl.h"
15 #include "llvm/ADT/STLExtras.h"
16 #include "llvm/IR/Attributes.h"
17 #include "llvm/IR/DiagnosticInfo.h"
18 #include "llvm/IR/Module.h"
19 #include "llvm/IR/OptBisect.h"
20 #include "llvm/Support/ManagedStatic.h"
21 #include <algorithm>
22 using namespace llvm;
23 
24 LLVMContextImpl::LLVMContextImpl(LLVMContext &C)
25   : TheTrueVal(nullptr), TheFalseVal(nullptr),
26     VoidTy(C, Type::VoidTyID),
27     LabelTy(C, Type::LabelTyID),
28     HalfTy(C, Type::HalfTyID),
29     FloatTy(C, Type::FloatTyID),
30     DoubleTy(C, Type::DoubleTyID),
31     MetadataTy(C, Type::MetadataTyID),
32     TokenTy(C, Type::TokenTyID),
33     X86_FP80Ty(C, Type::X86_FP80TyID),
34     FP128Ty(C, Type::FP128TyID),
35     PPC_FP128Ty(C, Type::PPC_FP128TyID),
36     X86_MMXTy(C, Type::X86_MMXTyID),
37     Int1Ty(C, 1),
38     Int8Ty(C, 8),
39     Int16Ty(C, 16),
40     Int32Ty(C, 32),
41     Int64Ty(C, 64),
42     Int128Ty(C, 128) {
43   InlineAsmDiagHandler = nullptr;
44   InlineAsmDiagContext = nullptr;
45   DiagnosticHandler = nullptr;
46   DiagnosticContext = nullptr;
47   RespectDiagnosticFilters = false;
48   DiagnosticHotnessRequested = false;
49   YieldCallback = nullptr;
50   YieldOpaqueHandle = nullptr;
51   NamedStructTypesUniqueID = 0;
52 }
53 
54 LLVMContextImpl::~LLVMContextImpl() {
55   // NOTE: We need to delete the contents of OwnedModules, but Module's dtor
56   // will call LLVMContextImpl::removeModule, thus invalidating iterators into
57   // the container. Avoid iterators during this operation:
58   while (!OwnedModules.empty())
59     delete *OwnedModules.begin();
60 
61   // Drop references for MDNodes.  Do this before Values get deleted to avoid
62   // unnecessary RAUW when nodes are still unresolved.
63   for (auto *I : DistinctMDNodes)
64     I->dropAllReferences();
65 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
66   for (auto *I : CLASS##s)                                                     \
67     I->dropAllReferences();
68 #include "llvm/IR/Metadata.def"
69 
70   // Also drop references that come from the Value bridges.
71   for (auto &Pair : ValuesAsMetadata)
72     Pair.second->dropUsers();
73   for (auto &Pair : MetadataAsValues)
74     Pair.second->dropUse();
75 
76   // Destroy MDNodes.
77   for (MDNode *I : DistinctMDNodes)
78     I->deleteAsSubclass();
79 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
80   for (CLASS * I : CLASS##s)                                                   \
81     delete I;
82 #include "llvm/IR/Metadata.def"
83 
84   // Free the constants.
85   for (auto *I : ExprConstants)
86     I->dropAllReferences();
87   for (auto *I : ArrayConstants)
88     I->dropAllReferences();
89   for (auto *I : StructConstants)
90     I->dropAllReferences();
91   for (auto *I : VectorConstants)
92     I->dropAllReferences();
93   ExprConstants.freeConstants();
94   ArrayConstants.freeConstants();
95   StructConstants.freeConstants();
96   VectorConstants.freeConstants();
97   InlineAsms.freeConstants();
98 
99   CAZConstants.clear();
100   CPNConstants.clear();
101   UVConstants.clear();
102   IntConstants.clear();
103   FPConstants.clear();
104 
105   for (auto &CDSConstant : CDSConstants)
106     delete CDSConstant.second;
107   CDSConstants.clear();
108 
109   // Destroy attributes.
110   for (FoldingSetIterator<AttributeImpl> I = AttrsSet.begin(),
111          E = AttrsSet.end(); I != E; ) {
112     FoldingSetIterator<AttributeImpl> Elem = I++;
113     delete &*Elem;
114   }
115 
116   // Destroy attribute lists.
117   for (FoldingSetIterator<AttributeListImpl> I = AttrsLists.begin(),
118                                              E = AttrsLists.end();
119        I != E;) {
120     FoldingSetIterator<AttributeListImpl> Elem = I++;
121     delete &*Elem;
122   }
123 
124   // Destroy attribute node lists.
125   for (FoldingSetIterator<AttributeSetNode> I = AttrsSetNodes.begin(),
126          E = AttrsSetNodes.end(); I != E; ) {
127     FoldingSetIterator<AttributeSetNode> Elem = I++;
128     delete &*Elem;
129   }
130 
131   // Destroy MetadataAsValues.
132   {
133     SmallVector<MetadataAsValue *, 8> MDVs;
134     MDVs.reserve(MetadataAsValues.size());
135     for (auto &Pair : MetadataAsValues)
136       MDVs.push_back(Pair.second);
137     MetadataAsValues.clear();
138     for (auto *V : MDVs)
139       delete V;
140   }
141 
142   // Destroy ValuesAsMetadata.
143   for (auto &Pair : ValuesAsMetadata)
144     delete Pair.second;
145 }
146 
147 void LLVMContextImpl::dropTriviallyDeadConstantArrays() {
148   bool Changed;
149   do {
150     Changed = false;
151 
152     for (auto I = ArrayConstants.begin(), E = ArrayConstants.end(); I != E;) {
153       auto *C = *I++;
154       if (C->use_empty()) {
155         Changed = true;
156         C->destroyConstant();
157       }
158     }
159 
160   } while (Changed);
161 }
162 
163 void Module::dropTriviallyDeadConstantArrays() {
164   Context.pImpl->dropTriviallyDeadConstantArrays();
165 }
166 
167 namespace llvm {
168 /// \brief Make MDOperand transparent for hashing.
169 ///
170 /// This overload of an implementation detail of the hashing library makes
171 /// MDOperand hash to the same value as a \a Metadata pointer.
172 ///
173 /// Note that overloading \a hash_value() as follows:
174 ///
175 /// \code
176 ///     size_t hash_value(const MDOperand &X) { return hash_value(X.get()); }
177 /// \endcode
178 ///
179 /// does not cause MDOperand to be transparent.  In particular, a bare pointer
180 /// doesn't get hashed before it's combined, whereas \a MDOperand would.
181 static const Metadata *get_hashable_data(const MDOperand &X) { return X.get(); }
182 }
183 
184 unsigned MDNodeOpsKey::calculateHash(MDNode *N, unsigned Offset) {
185   unsigned Hash = hash_combine_range(N->op_begin() + Offset, N->op_end());
186 #ifndef NDEBUG
187   {
188     SmallVector<Metadata *, 8> MDs(N->op_begin() + Offset, N->op_end());
189     unsigned RawHash = calculateHash(MDs);
190     assert(Hash == RawHash &&
191            "Expected hash of MDOperand to equal hash of Metadata*");
192   }
193 #endif
194   return Hash;
195 }
196 
197 unsigned MDNodeOpsKey::calculateHash(ArrayRef<Metadata *> Ops) {
198   return hash_combine_range(Ops.begin(), Ops.end());
199 }
200 
201 StringMapEntry<uint32_t> *LLVMContextImpl::getOrInsertBundleTag(StringRef Tag) {
202   uint32_t NewIdx = BundleTagCache.size();
203   return &*(BundleTagCache.insert(std::make_pair(Tag, NewIdx)).first);
204 }
205 
206 void LLVMContextImpl::getOperandBundleTags(SmallVectorImpl<StringRef> &Tags) const {
207   Tags.resize(BundleTagCache.size());
208   for (const auto &T : BundleTagCache)
209     Tags[T.second] = T.first();
210 }
211 
212 uint32_t LLVMContextImpl::getOperandBundleTagID(StringRef Tag) const {
213   auto I = BundleTagCache.find(Tag);
214   assert(I != BundleTagCache.end() && "Unknown tag!");
215   return I->second;
216 }
217 
218 /// Singleton instance of the OptBisect class.
219 ///
220 /// This singleton is accessed via the LLVMContext::getOptBisect() function.  It
221 /// provides a mechanism to disable passes and individual optimizations at
222 /// compile time based on a command line option (-opt-bisect-limit) in order to
223 /// perform a bisecting search for optimization-related problems.
224 ///
225 /// Even if multiple LLVMContext objects are created, they will all return the
226 /// same instance of OptBisect in order to provide a single bisect count.  Any
227 /// code that uses the OptBisect object should be serialized when bisection is
228 /// enabled in order to enable a consistent bisect count.
229 static ManagedStatic<OptBisect> OptBisector;
230 
231 OptBisect &LLVMContextImpl::getOptBisect() {
232   return *OptBisector;
233 }
234